Generally, the invention relates to vacuum cleaners. Particularly, the invention relates to an improved conversion valve assembly design for a floor care appliance such as a vacuum cleaner.
The use of conversion valve arrangements in upright vacuum cleaners is old and well known in the art. Automatic cleaner conversion is also known to be occasioned by movement of the cleaner handle to an upright stored position, with this movement driving the conversion valve to a converted hose operating position. An example of such an arrangement can be found in U.S. Pat. No. 5,351,361 issued to Buchtel and owned by a common assignee. However, no provision is made in such a conversion valve arrangement for the contingency of an object getting stuck in the suction duct and preventing the valve door from closing. In such a case, the large torque produced by pushing the elongated vacuum cleaner handle into the upright position can break and/or damage the linkages of the conversion valve assembly which are generally driven by the movement of the upright housing and cleaner handle.
Accordingly, it is an object of the invention to provide an upright cleaner having an improved conversion valve assembly operated by the movement of the cleaner handle.
A further object of the invention is to provide an improved conversion valve assembly wherein the linkages driving the conversion valve will not be damaged or broken by moving the cleaner handle into the upright position when the conversion valve door is stuck in the open position.
These and other objectives will be readily apparent from the following description taken in conjunction with the accompanying drawings.
In carrying out the invention in one aspect thereof, these objectives and advantages are obtained by providing an upright vacuum cleaner having a conversion valve for converting the cleaner from floor use to off-the-floor use. A conversion valve assembly is provided which automatically closes a conversion valve to shut off the suction provided to the agitator chamber when the cleaner handle and upright housing are moved to the upright position. A projection on the front of the upright housing cooperates with a rear valve arm to drive and hold the conversion valve in the shut position when the cleaner handle and upright housing are moved into the upright stored position. The suction from a suction motor is shut off to the agitator chamber and all suction is directed to the off-the-floor accessory hose. The conversion valve remains in the closed position until the cleaner handle and upright housing are released from the upright position. The projection on the front of the upright housing releases the rear valve arm freeing the valve arm to rotate freely about a pivot. The suction from the suction motor or a spring member causes the conversion valve to move into the open position. In an alternate embodiment of the invention, a spring member causes the conversion valve to move into the open position.
The conversion valve has a crank arm connected to a front valve arm for moving the conversion valve to the closed position when the cleaner handle and upright housing are moved to the upright stored position. The front valve arm cooperates with the rear valve arm when the projection on the front of the housing engages the rear valve arm when the cleaner handle and upright housing are moved into the upright stored position. The front valve arm and rear valve arm are pivotally connected and cooperate with each other via a torsion spring. The torsion spring transmits the mechanical movement created by the projection on the front of the upright housing when the upright housing and cleaner handle are moved into the upright position to the front valve arm, and the crank arm of the conversion valve to move the conversion valve into the closed position. However, should a stuck object prevent the conversion valve from closing, damage to the conversion valve, crank arm, front valve arm, rear valve arm, and front projection is prevented because the resiliency of the torsion spring allows the rear crank arm and the front crank arm to pivot relative to each other when the projection depresses the rear crank arm when the upright housing and cleaner housing are moved into the upright stored position.